针对深圳市某饮用水厂供水管网水质进行了为期 1 年的调查监测研究.结果表明,供水管网取样点常规水质指标相对稳定,而管网水末端混浊度较出厂水升高了 123.1%.相关性分析表明,高消毒剂的投加量能够有效控制管网中细菌的数量(R=-0.46,p≤0.001),同时抑制细菌对AOC的摄取.虽然增加消毒剂的投加量能有效抑制管网中细菌的活动,却也增加了水厂运营成本与消毒副产物生成的风险,建议水厂加强对AOC的监测与控制,供给优质饮用水.利用固相萃取和液相色谱质谱联用技术分析了深圳市某水厂供水管网中 38 种PPCPs和 7 种EDCs,并对新污染物的环境风险熵进行了评估.38 种PPCPs在管网末端的风险熵均小于 1,而EDCs中炔雌醇的风险熵(132.5)远超高风险限值,需要重点关注.
近年来,许多学者针对铁基材料在城市水处理中的应用进行了深入研究,包括在给水处理中的混凝和消毒作用,在排水管网中对硫化物的抑制作用,在污水处理系统中对除磷、污泥脱水与厌氧消化的强化作用、对自然黑臭水体的改善作用等方面.研究结果表明了铁基材料在水处理系统有非常广泛的应用潜力.不同于传统药剂,铁基材料在城市水循环过程中可以回收使用.基于铁基材料在实现城市水管理的可持续性方面具有巨大的潜力,围绕给水处理系统、污水管网系统、污水处理系统、自然黑臭水体四个方面,综述了铁基材料在城市水循环过程中的应用效果、机理和目前存在的问题,以期更好地优化铁基材料的应用潜力.
建立了膜性能评价体系,包括实验室检测与现场中试两大部分.通过现场中试研究,考察超滤膜系统对水质的提升效果,探究给水工艺应用超滤膜技术的必要性,结合跨膜压差、膜污染成分分析以及超滤膜一般性能表征,分析超滤膜抗污染能力以及超滤膜长期运行的稳定性.研究结果表明,全流程工艺增加超滤单元可以进一步提升供水水质;膜孔径分布不均将导致跨膜压差增幅较大,抗污染能力较弱;超滤膜长期运行后,膜亲水性将有所降低,但膜机械强度变化不明显.
For gravity flow diversion projects,pressure regulating valves are generally used at the tail to achieve flow control and energy dissipation.A water diversion project in southwestern Hubei Province takes water from the reservoir and transports it to the main water plant in the ur-ban area.The transportation distance is about 25 km.The difference between the normal water level of the reservoir and the elevation of the water plant is about 280 m.If the pressure regulating valve is still used for energy dissipation,it will cause a great waste of water head.In view of the actual situation of high drop,energy dissipation power stations are set up in the middle of the pro-ject to reduce pressure.The installed capacity of the power station is 8 MW,the annual power gen-eration is 62.35 million kW·h,and the investment in unit electric energy is only = Y1.6/(kW·h),which makes full use of water resources and has good economic benefits.
A wastewater treatment project has been implemented in southwest of China specif-ically for treating the carbon nanotube conductive liquid production wastewater generated by power battery manufacturing.The project employs a comprehensive treatment process that combines physical and chemical coagulation precipitation,sand filter,resin adsorption,ultrafiltration(UF),two-stage reverse osmosis(RO),electrodialysis(ED),and a mechanical vapor dual recompression system(MVDR).The treatment facility has a designed capacity of 300 m3/d.The wastewater comprises mainly purified wastewater,vacuum pump wastewater,and initial rainwater,with ex-ceptionally high levels of total nitrogen,hardness,and total nickel.Following the treatment process,the effluent water quality meets The reuse of urban recycling water—Water quality standard for industrial uses(GB/T 19923-2005)for boiler recharge water,with the total nitro-gen remaining consistently below 40 mg/L,total nickel remaining consistently below 0.1 mg/L.Furthermore,a mechanical vapor dual recompression system(MVDR)is employed to evaporate and crystallize sodium nitrate,resulting in salt purity exceeding 98%and meeting the general in-dustrial salt standard.Since the project commencement in May 2023,the wastewater treatment project has demonstrated stable operation,consistently achieving excellent effluent water quality.Notably,the project has successfully achieved zero discharge of wastewater,contributing to envi-ronmental sustainability and resource conservation.
The secondary water supply system has the problem of pipe port corrosion,which poses a risk of deteriorating water quality and thus posing a threat to customers'health.This stud-y investigates the effect of steel-plastic composite pipe and 304 thin-walled stainless steel pipe on the corrosion resistance of ports when different connection methods are used when chloride ions and pH are the corrosive media.The results showed that the steel-plastic composite pipe showed signif-icant differences in corrosion resistance between the ports under the two connection methods of screwed and grooved,the highest total iron concentration of grooved connection(1 127.47 μg/L)is nearly ten times higher than that of screwed connection(121.53 μg/L).304 thin-walled stainless steel clamping,double clamping and grooved connection benefits from the tube itself corrosion re-sistance are not serious corrosion phenomena,but there are certain differences.The clamping con-nection has the highest average corrosion rate in the polarization curve test(0.009 mm/a)and the highest total iron concentration of 92.07 μg/L with poor corrosion resistance,exceeding the other two connection methods by more than 90%.The difference in total iron concentration is about 5 μg/L and the highest total iron concentration is less than 50 μg/L under each condition of double clamping connection and grooved connection,which has good corrosion resistance,the same results were obtained using the pilot plant.However,the grooved connection has a certain tendency to corrode with a mean corrosion rate of 0.007 mm/a under low pH conditions.The results of this study illustrate the effect of different pipe connection methods on the corrosion resistance of the ports,which can help the selection of pipes and connection methods for secondary water supply systems under different water quality conditions.
Greenhouse gas emission control is an important national policy of China and a com-mitment to the international community.How to achieve low carbon emissions throughout the life cycle of the water supply system on the basis of meeting the safety service objectives such as water quality,water quantity and water pressure and its own safety production is an important task at present.In this paper,the carbon emission calculation method is analyzed,and then a life cycle greybox model is proposed,which is applied in two water supply systems such as virtual town and virtual city,and the influencing factors of carbon emissions and carbon emissions of the national water supply system are obtained.Also the carbon emission reduction route including renewable energy and general energy-saving equipment,water treatment processes and technologies,water transmission and distribution systems,and smart water affairs was proposed according to the cur-rent situation in China,and the carbon emission reduction process technologies,methods and standardization innovation such as photovoltaic,hydroturbine power generation,coagulation,chemical dosing and carbonate/bicarbonate decomposition control,membrane filtration and combi-nation process,ozonation process,disinfection process,energy saving of water transmission and distribution pumping stations,leakage control,pipeline repair and updating,and intelligent pum-ping stations were analyzed.Through the joint efforts of all participants and the implementation of the carbon emission reduction roadmap proposed in this paper,it is expected that the life cycle car-bon emission factor of China's public water supply system can be reduced from current 0.335 kg CO2e/m3 to 0.294 kg CO2e/m3 in terms of water supply,and total carbon emission from 3.1579×1010 kg CO2e/a to 2.3545×1010 kg CO2e/a,which not only has significant carbon reduction bene-fits,but also supports the carbon emission competitiveness of related industries.
To quantitatively analyze the carbon emissions per unit of stormwater regulation ca-pacity of LID facilities,the concepts of carbon emission intensity of life cycle runoff control volume and carbon reduction benefit were proposed and studied for a new 750kV substation in Gansu Prov-ince.The results show that the combined scheme of bioretention and permeable paving has a vol-ume capture ratio of annual rainfall of 85.11%and the peak runoff reduction rate of 70%under the 5-year return period,which has a better total runoff control as well as a better peak runoff reduc-tion effect on the stormwater of the substation.The carbon emission intensity of the LID facilities during its 30-year lifecycle is 0.94 kgCO2/m3 total runoff control volume,which indicates that the more runoff the LID facilities control over their 30-year life cycle,the less carbon emissions it pro-duces.The carbon sink of the facilities in the 30-year life cycle can neutralize the carbon emissions in the construction phase.The carbon reduction benefit is 0.34 kgCO2/yuan,which has an excel-lent economic value.
Aiming at the technical problems of leakage control of urban water distribution sys-tem,a large and medium-sized pipe network in CY area of a northern city is taken as the research object,and the hydraulic characteristics of each node,pipe,pump station and pressure reducing valve in the pipe network are comprehensively analyzed,and a pressure control model with inte-grated valve and pump station is proposed to optimize the redundant pressure of the pipe network and reduce the leakage rate of the pipe network,and the analysis and calculation of the leakage a-mount of the pipe network is carried out by using the nighttime minimum flow method.To address the shortcomings of insufficient population diversity and easy to fall into local convergence of the initial gray wolf optimization algorithm,the calculation of the linear convergence factor and the a-daptive assignment of the weights of the three guiding wolves are adjusted,and the hunting search strategy based on dimensional learning is introduced to improve it,and then it is applied to the op-timization search calculation of the actual project,and the optimal regulation scheme of the pres-sure reducing valve and variable speed pump is derived.The results demonstrate that the proposed scheme has a significant effect on reducing redundant pressure and controlling leakage by selecting typical time periods for operating analysis of the pipeline network conditions.
Electro-chemical energy storage stations using lithium iron phosphate batteries as energy storage media pose a high fire risk.When firefighting water is used to extinguish fires in these stations,a large amount of firefighting wastewater is discharged.Lithium iron phosphate batteries are composed of lithium salt electrolytes,electrolytes,and other complex components.Currently,there is a lack of research on the water quality of firefighting wastewater from these bat-teries,and there is controversy over the discharge of firefighting wastewater in practical engineer-ing applications.To address this issue,combustion and firefighting experiments were conducted on 100 Ah lithium iron phosphate batteries with different degrees of age and charging,and their fire-fighting wastewater was collected and tested.The test results showed that the firefighting wastewater was neutral in pH,and the concentrations of copper,nickel,chromium,lead,manga-nese,arsenic,TN and NH3-N did not exceed relevant emission standards.However,the concen-trations of fluoride ions and total phosphorus were relatively high.The COD values of the firefight-ing wastewater were high.Comparison of the experimental data with engineering design parame-ters showed that the firefighting wastewater from lithium iron phosphate battery energy storage power station,most pollutant indicators are lower than relevant emission standards,some indica-tors are higher,but the total amount of pollutants is relatively small Therefore,emergency dis-charge of firefighting wastewater in the event of a fire will not cause significant environmental pol-lution.For energy storage power stations built in regions with high standard of environmental pro-tection,it is recommended that the wastewater is collected in place or transported to other place af-ter collecting.
In China,the treatment of urban water environment has entered the systematic treatment stage that is aimed to control environmental quality.It summarized the effects and defi-ciencies of water environment treatment in the background of traditional treatment,which include wastewater treatment plant,pipe network,river and lake,etc.It analyzed the causes that led to the problems and dilemmas of urban water environmental treatment from the perspective of man-agement mechanism,governance model and technical support system.It provided ideas for the transformation of urban water environment rehabilitation in China.
This paper takes the building water supply and drainage and water fire extinguishing design of an office complex in a core business district of Shanghai as an example.The design fea-tures and problems are discussed.There are emphasized in the design measures of green ecological urban area,rainwater drainage,collection and utilization,the configuration of large space fire pump and the connection of building buildings fire water supply pipeline.The business core area develops from green buildings to green ecology,and implements the technical measures of water supply and drainage for carbon peak and carbon neutrality.In order to pay attention to the problem of flood control and drainage in large underground space,the rainwater drainage methods and treat-ment forms of underground space structure drainage in different areas such as building retreating platform,roof greening and overall site are given,and the layout of indoor hydrant pipe network and fire water supply main pipe is compared.
At present,for the concept and/or approach of biodosimetry of ultraviolet(UV)dose for water disinfection,various nomenclatures have been used in Chinese literatures(including national standards and industrial standards),which leads to the inconsistency of the concepts.This paper is set to discuss,analyze and summarize original concepts and methods of concern in stand-ards and literatures,and to put forward some recommendations for unifying the Chinese nomencla-ture of biodosimetry,or bio-assay dose.
The design scale of a centralized wastewater treatment plant in a fine chemical indus-trial park in northwest China is 1 5000 m3/d.The wastewater is mainly composed of biochemical,pesticide,and pharmaceutical intermediates.The water shows high loading,poor biodegradability,and contains toxic pollutants such as aniline,nitrobenzene,and benzene series.To meet the high discharge standards,an enhanced pre-treatment units can bio detoxify raw water while improving biodegradability,releasing the treatment potential of the secondary biological treatment units.The main process adopts iron carbon micro electrolysis coupling Fenton oxidation tank,hydrolysis acid-ification tank,five-stage Bardenpho bioreactor,secondary sedimentation tank,magnetic coagula-tion clarification tank,ozone contact tank,aeration biological filter,and denitrification deep bed filter.The operation results show that the process combination greatly treats industrial wastewater in the park.The main pollutant indicators of the effluent can stably meet the Class Ⅳ water stand-ard(TN≤15 mg/L)specified in the Environmental quality standards for surface water(GB 3838-2002),and the total cost per unit of water treatment is about 7.45 RMB when using this process.
Municipal sludge treatment and disposal is an important component that cannot be ignored in the field of carbon reduction.This study combined the emission factor method and actual operating parameters in the project case to calculate the carbon footprint of three promising tech-nology route:anaerobic digestion+thermal drying+collaborative disposal of cement kiln,biologi-cal drying+thermal drying+collaborative disposal of cement kiln,and biological drying+pyrolysis +collaborative disposal of cement kiln.The results showed that the carbon emission of the tech-nology route of biological drying+thermal drying+collaborative disposal of cement kiln was the lowest,which was mainly due to the low energy consumption of dehydration and high energy con-version efficiency in the process of biological drying.In order to further reduce the carbon emis-sions generated during anaerobic digestion and pyrolysis,the development of low-carbon sludge conditioning agents suitable for terminal disposal and the optimization of pyrolysis processes were the directions that need to be paid attention to in the future.At the same time,the optimization of conditioning agents,bactericides and control parameters can effectively improve the degradation ef-ficiency of organic matter in sludge,enhance the dehydration effect of biological drying,and was also expected to promote carbon emission reduction in sludge treatment.
The watershed comprehensive improvement project in the Guangdong-Hong Kong-Macao Greater Bay Area has attracted widespread attention,because of its system complexity,large administrative region and watersheds,numerous river systems,differentiated urban construc-tion,public welfare or semi-public welfare,and large investment.Although the initial success in management of water environment of the Greater Bay Area has been achieved,there is still a wide gap in its water environment quality compared to the world-class bay area,which needs to be fur-ther improved.This paper resolved the causes and characteristics of black and odorous water and conclude the management status and existing problems,via analyzing the characteristics of the wa-ter system and water quality in the Greater Bay Area.Furthermore,the paper expounds the main points and difficult problems faced at the present stage and proposes the working route,treatment scheme,technical measures for further comprehensive management.Meanwhile,this paper sug-gests that rural sewage treatment,rain and sewage diversion,overflow pollution control,and smart operation across administrative divisions will become the internal needs and development trends for the water environment quality upgrade in the Greater Bay Area.
Annular water supply technology with water appliances is an important way to en-sure the end water quality.It is widely used and mature in developed countries of European Union.In our infancy,engineering applications are few,aiming at the unclear calculation flow and unclear principle of pipe diameter selection,taking residential,hospital and canteen buildings as examples,refined hydraulic calculation and pipe diameter selection analysis were carried out.This paper sum-marizes the calculation flow determination method and pipe diameter selection principle of different types of building water appliances branch pipe ring pipe,which provides theoretical support for the practical engineering application of this technology,and provides reference for the formulation of standards.
The swift and imperative disposal of a substantial volume of waste sludge generated during routine maintenance of urban water facilities is of paramount concern.Owing to the intricate origins and constituents of waste sludge,a systematic and rational approach to resource disposal re-mains notably deficient.This research takes the waste sludge generated by representative water fa-cilities in Shenzhen as a case study,delving into the examination of the physical and chemical at-tributes of sludge across distinct stages of separation and varied sources.Subsequently,this study formulates strategies for the treatment and resourceful utilization of waste sludge.Based on the in-herent properties and characteristics of the sludge,the resultant screened products are categorized into three classes:inorganic coarse materials,organic screening slag,and a finely blended sand mixture.Practical application has validated the reclamation of waste sludge through the fabrication of non-sintered bricks using inorganic coarse materials,along with the production of waste-derived fuels from organic screening slag.Furthermore,the fine sand mixture exhibits potential for con-version into construction materials following advanced treatment,thereby enhancing the prospect of sand resource reuse.
Taking the pre-built gravity flow water transmission pipeline in a southeast moun-tainous county as an example,the reservoir water level,pipeline flow and valve closing point were selected as variables,and 12 operating conditions were obtained,and the hydraulic transient of these conditions under various valve closing times was simulated.During the transition process,the influence of three variables on the valve closing water hammer was analyzed,and the water hammer protection suggestions were put forward for each working condition.The results showed that the influence of the water level in the reservoir cannot be generalized;the larger the pipeline flow rate,the larger the influence of water hammer;the position of the valve closing point had a great influence on the water hammer,and the negative effects of water hammer could be eliminated by appropriately prolonging the valve closing time and adding an exhaust valve.The purpose of this study was to illustrate the complexity of gravity flow closing valve water hammer through an engi-neering examples,and it was suggested that the working conditions of water hammer analysis should be as comprehensive as possible,especially the working conditions under multiple valve closing points.
